The evolution of the modern hospital owes a significant debt to developments in the history of medicine in France during the period before the Revolution of 1789. An influential body of scientists and intellectuals set about to reform a hospital system whose form, goals and treatment of the sick had not significantly changed in European society since the time of the Crusades. The boldest and most original hospital planner in France during this period was Jacques Tenon (1724- 1816). Nothing of importance has yet been written on his medical thought and career although his recommendations for the construction and organization of hospitals along scientific principles were held to be definitive for over a century. His view of the hospital as a social institution, the key to any effective system of health care, a house of healing rather than a center of detention and relief, and at the same time an instrument of medical instruction and a center of study anticipated the objectives of the modern hospital movement. Tenon will be studied in the context of the practical application of the scientific and technological innovations of the Scientific Revolution of the 17th and 18th centuries to medicine and public health. The decisive role he played in the collaboration of the scientific community and government in shaping a national health policy will be explained. Tenon formulated a social philosophy which posited good health as a basic human right, which would safeguard the dignity and self-respect of the hospitalized sick, which saw in a healthy citizenry the key to national prosperity, which related public health to social welfare and expanded employment opportunity, which demonstrated the responsibility of government in protecting the suffering, the helpless and disadvantaged groups. The pre-Revolutionary hospital reform movement provided a forum in which wide-ranging medical and public health ideas were debated. These issues cannot be understood in isolation. They will be evaluated in the broader perspective of scientific, intellectual, ethicosocial and political forces which prepared the medical and hospital "revolutions" of the 19th and 20th centuries.